Do not panic if your four-month-old puppy starts barking from his crate in the middle of the night. The reasons for this behavior vary. To stop the barking, you must figure out why the dog is sounding off. Then you can take steps to change the behavior.
Dogs mature at various rates, and puppies may need to go outside for potty breaks during the night. Barking or whining in the middle of the night might mean that the dog needs to go outside. If you suspect that your pup needs relief, take him or her out to eliminate, but don't fuss. The Humane Society of the United States website says, "This should be a trip with a purpose, not play time. If you're convinced that your dog doesn't need to eliminate, the best response is to ignore him until he stops whining."
If you let your pup out of the crate when he or she barks, whines or cries, the pup will learn that crying gets your attention and turn the barking into a game. PetMD recommends a way to deal with this annoying problem: "When he starts to bark and whine, tap the door of the crate and say 'no' in a strong, commanding but not loud voice. With repetition, this will make him stop crying and eventually train him not to whine when he is placed inside his crate."
Sounding the Alarm
Your 4-month-old puppy is learning about his environment, and unfamiliar sounds may trigger barking. At night the dog might hear an alarm in another room, a passing car, barking dogs outside, cats on a fence and countless other distractions. To correct him when he's barking, give a firm "no" or tap on the crate as a correction. Advice from the Applied Ethology website says, "Keep in mind the punishment should be applied while the barking is occurring, in order for your dog to associate the unwanted behavior with the punishment. Also remember to reward your dog when [he] stops barking." The reward could be a softly spoken praise.
Try to establish a regular bedtime for your pup. Withhold food for a few hours before bed, and water for an hour before. Take the pup outside to eliminate, then put him in the crate with a favorite blanket or toy. Getting through the night with a puppy, like with a human baby, requires you rise a couple times through the night for changes and feeding. Luckily, puppies mature much quicker than human babies, so your sleep deprivation will be limited. With your consistency and understanding, your pup will soon sleep through the night.